Interfacial bonding, wettability and reactivity in metal-oxide systemsReport as inadecuate




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Abstract : Pure non-reactive metals develop weak interactions with iono-covalent oxides insulators which can be both physical van der Waals and chemical low density interfacial electronic states. As a result, non-wetting is generally observed, the contact angle being larger than 90 degrees. Improvement of wetting can be obtained by alloying the metal with a reactive solute B capable of modifying in a favourable sense the metal-oxide interface. This can be achieved via two mechanisms depending on the strength of the interactions between solute B and dissolved oxygen. For moderate O-B interactions, the solute B can modify the liquid-side of the interface by adsorption of OB clusters, the oxygen coming from the dissolution of the oxide substrate. This mechanism can lead to a decrease of θ down to ≈ 60○. For strong O-B interactions, the solute B can also lead to the precipitation at the solid-side of the interface of a new phase. When this new phase features metallic bonding, wetting can be strongly improved and nearly perfect wetting can be obtained.





Author: N. Eustathopoulos B. Drevet

Source: https://hal.archives-ouvertes.fr/



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